How does classes Inheritance work in Unity?
Create an Empty Object and attach the scripts.
FruitSalad.cs
public class FruitSalad : MonoBehaviour // estende MonoBehaviour, è la classe dalla quale ereditano tutti i componenti dei nostri giochi
{
void Start()
{
//Let's illustrate inheritance with the
//default constructors.
Debug.Log("Creating the fruit");
Fruit myFruit = new Fruit();
Debug.Log("Creating the apple");
Apple myApple = new Apple();
//Call the methods of the Fruit class.
//Now let's illustrate inheritance with the
//constructors that read in a string.
Debug.Log("Creating the fruit");
myFruit = new Fruit("yellow");// crea un'istanza della classe Fruit.cs
Debug.Log("Creating the apple");
myApple = new Apple("green"); // crea un'istanza della classe Apple.cs
//Call the methods of the Fruit class.
myFruit.SayHello(); // scrive: Hello. I am a fruit.
myFruit.Chop(); // scrive: The yellow fruit has been chopped
//Call the methods of the Apple class.
//Notice how class Apple has access to all
//of the public methods of class Fruit.
myApple.SayHello(); // scrive: Hello. I am a fruit.
myApple.Chop(); // scrive: The green fruit has been chopped
}
}
[/charp]
Fruit.cs
using UnityEngine;
using System.Collections;
//This is the base class which is
//also known as the Parent class.
public class Fruit
{
public string color;
//This is the first constructor for the Fruit class
//and is not inherited by any derived classes.
public Fruit() // deve esserci obbligatoriamente il costruttore che riceve 0 parametri
{
color = "orange";
Debug.Log("1st Fruit Constructor Called");
}
//This is the second constructor for the Fruit class
//and is not inherited by any derived classes.
public Fruit(string newColor)
{
color = newColor;
Debug.Log("2nd Fruit Constructor Called");
}
public void Chop()
{
Debug.Log("The " + color + " fruit has been chopped.");
}
public void SayHello()
{
Debug.Log("Hello, I am a fruit.");
}
}
Apple.cs
using UnityEngine;
using System.Collections;
//This is the derived class whis is
//also know as the Child class.
public class Apple : Fruit // Apple estende Fruit
{
//This is the first constructor for the Apple class.
//It calls the parent constructor immediately, even
//before it runs.
public Apple() // deve esserci obbligatoriamente il costruttore che riceve 0 parametri
{
//Notice how Apple has access to the public variable
//color, which is a part of the parent Fruit class.
color = "red"; // la proprietà color è in Fruit.cs
Debug.Log("1st Apple Constructor Called");
}
//This is the second constructor for the Apple class.
//It specifies which parent constructor will be called
//using the "base" keyword.
public Apple(string newColor) : base(newColor)
{
//Notice how this constructor doesn't set the color
//since the base constructor sets the color that
//is passed as an argument.
Debug.Log("2nd Apple Constructor Called");
}
}
On console:
– Creating the fruit
– 1st Fruit Constructor Called
– Creating the apple
– 1st Fruit Constructor Called
– 1st Apple Constructor Called
– Creating the fruit
– 2nd Fruit Constructor Called
– Creating the apple
– 2nd Fruit Constructor Called
– 2nd Apple Constructor Called
– Hello, I am a fruit
– The yellow fruit has been chopped
– Hello, I am a fruit
– The green fruit has been chopped
For italian people:
1. Fruit myFruit = new Fruit(); -> public Fruit(), il costruttore senza parametri
2. Apple myApple = new Apple(); -> public Fruit() poi public Apple()
3. myFruit = new Fruit(“yellow”); -> public Fruit(string newColor)
4. myApple = new Apple(“green”); -> -> public Fruit(string newColor) poi public Apple(string newColor) : base(newColor) specifica la chiamata al costruttore di Fruit.cs tramite la keyword : base(newColor) – estende newColor
5. Fruit.cs scrive Debug.Log(“Hello, I am a fruit.”); e Debug.Log(“The ” + color + ” fruit has been chopped.”);
